1. Field of the Invention
The present invention relates to a musical-tone-generating-control apparatus that controls the generation of musical-tone signals by delivering tone-pitch data to one of the musical-tone-signal-generating channels which constitutes a musical-tone-signal-generating circuit, and which also controls the tone-color of the musical-tone signals by supplying tone-color-control parameters stored in tone-color-parameter memory to the musical-tone-signal-generating .circuit
2. Prior Art
A conventional apparatus of this type is described in the Japanese Patent Preliminary Publication No. sho 59-189394. It is provided with a plurality of musical-tone-signal-generating channels in a musical-tone-signal-generating circuit. Each channel is allocated to one of the tone groups such as a melody group, a chord group, a base group, etc., before performance. Once allocated, the allocation of channels is fixed during the performance, and tone-color data in every tone group is applied to a predetermined channel. For example, tone-pitch data relating to a melody part is supplied to the musical-tone-signal-generating channel allocated for melody; tone-pitch data relating to a chord part is transferred to the musical-tone-signal-generating channel for the chord, thus producing different tone colors depending on the tone group.
The conventional apparatus has a fixed and limited number of musical-tone-signal-generating channels for each tone group. This limits the maximum number of tones which can be generated in each tone group, and it causes the utilization efficiency of the musical-tone-signal-generating channels to decrease; even if there is a tone group with vacant channels, they cannot be used by the other groups. For example, when the number of musical tones belonging to the melody group exceeds the maximum number thereof, the melody group cannot handle some melody tones even if channels belonging to other groups are empty.
To counteract this disadvantage, it may be possible to supply tone-pitch data corresponding to musical tones to be generated, to each of the musical-tone-signal-generating channels, together with tone-color-control parameters for controlling the musical tone colors, so that the generation of musical-tone signal and the controlling of tone colors thereof are simultaneously performed at each channel.
The tone-color-control parameters used for generating each musical-tone signal, however, have increased recently in order to achieve high-quality musical tones. For this reason, if these numerous parameters must be transferred to the musical-tone-signal-generating channels every time tone-pitch data is applied thereto, the generation of musical-tone signals will be delayed because the transfer of these parameters requires much time, and this in turn retards other processes.